Are Changes in Dynamic Knee Movement Control Related to Changes in Pain or Function in People With Knee Disorders? A Systematic Review and Meta-analysis.

OBJECTIVE: To study whether changes in dynamic knee valgus or varus were associated with changes in pain or function in people with knee disorders. DESIGN: Systematic review with meta-analysis. LITERATURE SEARCH: We searched the MEDLINE, Embase, CINAHL, SPORTDiscus, Cochrane Library, and Web of Science, from inception up to January 2023. STUDY SELECTION CRITERIA: We included randomized controlled trials investigating the effects of nonsurgical (including nonpharmacological) interventions for knee disorders on frontal and transverse plane knee and hip movements during functional tasks, which reported pain and/or function outcomes. DATA SYNTHESIS: The relationship between changes in kinematics and pain/function was analyzed using a 2-stage structural equation modeling approach. RESULTS: From 42 202 records, 48 trials met the eligibility criteria. For people with patellofemoral pain (25 trials, n = 894), there was moderate evidence that changes in the knee and hip movements were significantly correlated with changes in pain and function (r= -0.69 to 0.73), except for the knee transverse plane movements and for the relationship between hip transverse plane movement and function. For people with knee osteoarthritis (15 trials, n = 704) and anterior cruciate ligament injuries (8 trials, n = 198), the evidence was limited and uncertain. CONCLUSION: The relationship between changes in movement control and clinical outcomes was consistent in people with patellofemoral pain. For people with knee osteoarthritis or anterior cruciate ligament injuries, there was a paucity of evidence that precluded a proper evaluation of the relationship between dynamic knee movement control, and pain and function. J Orthop Sports Phys Ther 2023;53(7):1-14. Epub: 18 April 2023. doi:10.2519/jospt.2023.11628.

Indeed, Correlation Does Not Indicate Causation!

Author response to the JOSPT Letter to the Editor-in-Chief "Lower-Limb Kinematics and Clinical Outcomes: Correlation Does not Imply Causality" J Orthop Sports Phys Ther 2023;53(11):723-725. doi:10.2519/jospt.2023.0203-R.

Quantitative G6PD Deficiency Screening in Routine Malaria Diagnostic Units in the Brazilian Amazon (SAFEPRIM): An Operational Mixed-Methods Study.

BACKGROUND: Glucose-6-phosphate dehydrogenase (G6PD) deficiency testing is not routinely performed before primaquine treatment in most Plasmodium vivax endemic areas, despite the risk of primaquine-associated hemolysis. This is due to the operational challenges associated with pragmatic G6PD testing and as such needs to be addressed. METHODS AND FINDINGS: This mixed-methods operational study was aimed at implementing the quantitative point-of-care StandardTM G6PD (SD Biosensor, Korea) screening test in malaria treatment units (MTUs) in the municipalities of Rio Preto da Eva and Mâncio Lima, in the Brazilian Amazon, between mid-January 2020 and December 2020. In total, 1286 P. vivax cases were treated based on the Standard G6PD test: 1230 had activity equal to or greater than 4.0 U/g Hb, and 56 less than 4.0 U/g Hb. No G6PD deficient (G6PDd) genotypes were found in 96 samples from the 1230, and only 21 of the 56 G6PDd cases had confirmed G6PDd genotypes. Evaluations were conducted on the proficiency of health care professionals (HCPs) training to perform the test, the reliability of testing performed in the field, and the perceptions of HCPs and patients about the implementation. Post-training proficiency was 73.4% after a 4-hour training session. This study revealed that locations with lower malaria caseloads will need regular refresher training. The test was well accepted by both HCPs and patients. Signs and symptoms of hemolysis were not always associated with malaria treatment drugs by HCPs and patients. INTERPRETATION: Point-of-care quantitative G6PD testing can be performed at MTUs in the Brazilian Amazon to inform treatment decisions with primaquine. Limitations related to technical and cultural aspects need to be addressed further when expanding screening to larger areas.

The relationship between urinary C-Telopeptide fragments of type II collagen, knee joint load, pain, and physical function in individuals with medial knee osteoarthritis.

OBJECTIVE: Considering the osteoarthritis (OA) model that integrates the biological, mechanical, and structural components of the disease, the present study aimed to investigate the association between urinary C-Telopeptide fragments of type II collagen (uCTX-II), knee joint moments, pain, and physical function in individuals with medial knee OA. METHODS: Twenty-five subjects radiographically diagnosed with knee OA were recruited. Participants were evaluated through three-dimensional gait analysis, uCTX-II level, the WOMAC pain and physical function scores, and the 40m walk test. The association between these variables was investigated using Pearson's product-moment correlation, followed by a hierarchical linear regression, controlled by OA severity and body mass index (BMI). RESULTS: No relationship was found between uCTX-II level and knee moments. A significant correlation between uCTX-II level and pain, physical function, and the 40m walk test was found. The hierarchical linear regression controlling for OA severity and BMI showed that uCTX-II level explained 9% of the WOMAC pain score, 27% of the WOMAC physical function score, and 7% of the 40m walk test. CONCLUSION: Greater uCTX-II level is associated with higher pain and reduced physical function and 40m walk test performance in individuals with medial knee OA.

Real-life implementation of a G6PD deficiency screening qualitative test into routine vivax malaria diagnostic units in the Brazilian Amazon (SAFEPRIM study).

BACKGROUND: Glucose-6-phosphate dehydrogenase (G6PD) deficiency greatly hinders Plasmodium vivax malaria radical cure and further elimination due to 8-aminoquinolines-associated hemolysis. Although the deleterious health effects of primaquine in G6PD deficient individuals have been known for over 50 years, G6PD testing is not routinely performed before primaquine treatment in most P. vivax endemic areas. METHOD/PRINCIPAL FINDINGS: The qualitative CareStart G6PD screening test was implemented in 12 malaria treatment units (MTUs) in the municipality of Rio Preto da Eva, Western Brazilian Amazon, a malaria endemic area, between February 2019 and early January 2020. Training materials were developed and validated; evaluations were conducted on the effectiveness of training health care professionals (HCPs) to perform the test, the interpretation and reliability of routine testing performed by HCPs, and perceptions of HCPs and patients. Most HCPs were unaware of G6PD deficiency and primaquine-related adverse effects. Most of 110 HCPs trained (86/110, 78%) were able to correctly perform the G6PD test after a single 4-hour training session. The test performed by HCPs during implementation showed 100.0% (4/4) sensitivity and 68.1% (62/91) specificity in identifying G6PD deficient patients as compared to a point-of-care quantitative test (Standard G6PD). CONCLUSIONS/SIGNIFICANCE: G6PD screening using the qualitative CareStart G6PD test performed by HCPs in MTUs of an endemic area showed high sensitivity and concerning low specificity. The amount of false G6PD deficiency detected led to substantial loss of opportunities for radical cure.

Y-Balance Test Asymmetry and Frontal Plane Knee Projection Angle During Single-leg squat as Predictors of Patellofemoral Pain in Male Military Recruits.

OBJECTIVES: Investigate prospectively whether dynamic balance and frontal plane knee projection angle (FPKPA) are risk factors for the development of patellofemoral pain (PFP) in male military recruits. STUDY DESIGN: Prospective cohort. SETTING: Military training center. PARTICIPANTS: 135 male military recruits were followed prospectively for six weeks and the incidence of PFP was documented. MAIN OUTCOMES: Baseline measures of the Y-Balance test (YBT) and two-dimensional FPKPA during single-leg squatting were recorded. Mann-Whitney U tests and logistic regression analysis were utilized to identify possible variables associated with the development of PFP. RESULTS: A total of 14 male recruits developed PFP during the follow up period. The PFP group had significantly greater asymmetry on the YBT posterolateral direction (mean difference = 3.44 ± 0.57 cm; 95% Confidence Interval [CI] = 2.38-4.51 cm) and greater FPKPA during single-leg squat (mean difference = 5.55°±1.78°; [CI] = 1.81-9.28°) at baseline when compared to controls. Binary logistic regression models revealed that YBT posterolateral asymmetry ≥4.08 cm (Nagelkerke R2 = 0.304; X2 = 21.63; p < 0.001; OR = 5.46; [CI] = 4.47-8.06) and FPKPA ≥ 4.81° (Nagelkerke R2 = 0.249; X2 = 17.46; p < 0.001; OR = 4.65; [CI] = 3.32-9.06) were significantly associated with PFP. CONCLUSIONS: Male military recruits with greater asymmetry on the YBT posterolateral direction and FPKPA were at a greater risk of developing PFP.

Translation, adaptation and validation of the Nurse-Work Instability Scale to Brazilian Portuguese. / Tradução, adaptação e validação da Escala de Instabilidade no Trabalho de Enfermagem para português brasileiro.

OBJECTIVE: to translate, adapt and test the psychometric properties of the Brazilian Nurse-Work Instability Scale. METHOD: this was a methodological study following the translation steps: synthesis, back-translation, specialist´s committee, semantics analysis, pretest, and psychometric tests. The committee was composed of 5 specialists. For the semantics analysis, 18 nursing workers evaluated the instrument and 30 pretested it. For the psychometric tests, the sample size was 214 nursing workers. The internal construct validity was analyzed by the Rasch model. Reliability was assessed using internal consistency, and concurrent validity with Pearson's correlation between the Nurse-Work Instability Scale, and the Work Ability Index, Job Stress Scale. RESULTS: a Nurse-Work Instability Scale in Brazilian Portuguese with 20 items showed an adequate reliability (0.831), stability (p <0.0001), and an expected correlation with Work Ability Index (r = -0.526; P<0.0001) and Job Stress Scale (r = 0.352; p <0.0001). CONCLUSION: the instrument is appropriated to detect work instability in Brazilian nursing workers with musculoskeletal disorders. Its application is fundamental to avoid long-term withdrawal from work by early identification of the work instability. Furthermore, the scale can assist the development of actions and strategies to prevent the abandonment of the profession of nursing workers affected by musculoskeletal disorders.

Patellofemoral joint stress measured across three different running techniques.

BACKGROUND: Patellofemoral pain (PFP) is the most common running-related injury. It has been shown in previous studies that gait retraining may have a beneficial effect on patellofemoral joint stress (PFJS). RESEARCH QUESTION: Is there a reduction of PFJS across 4 running conditions: 1. runner's typical rearfoot strike pattern, 2. forefoot landing, 3. step rate increase by 10% and 4. forward trunk lean? METHODS: Nineteen healthy runners (28.05 ± 5.03 years; 26.58 ± 8.85 km/week, 6.00 ± 4.51 years of running experience) completed one running trial for each condition, at the same subject-specific comfortable speed on a treadmill. Kinetic and kinematic data were collected and measures of hip, knee and ankle joint moments and PFJS were calculated. RESULTS: Compared to rearfoot strike condition, peak PFJS and PFJS-time integral per step were significantly (P < 0.01) lower during forefoot landing and step rate increase conditions. PFJS per kilometer was significantly reduced for forefoot landing (17.01%; P < 0.01) and increased step rate (12.90%; P = 0.003). Forward trunk lean technique showed no significant differences in peak PFJS (P = 0.187), PFJS-time integral per step (P = 0.815) and PFJS per kilometer (P = 0.077) compared to rearfoot strike pattern. INTERPRETATION: The comparison between techniques revealed greater reductions on PFJS by forefoot landing, followed by 10% step rate increase condition. These changes were the result of different lower limb movement strategies across the 2 running conditions. We conclude that compared to a rearfoot strike pattern, both a forefoot landing and step rate increase result in lower cumulative PFJS joint stress in healthy runners, with the forefoot landing being the most effective. These running technique modifications could be recommended to reduce PFJS loads and may have implications for PFP prevention.

Differences in Timed Up and Go Subtasks Between Older People With Mild Cognitive Impairment and Mild Alzheimer's Disease.

This study compared performances of timed up and go test subtasks between 40 older people with preserved cognition, 40 with mild cognitive impairment, and 38 with mild Alzheimer's disease. The assessment consisted of anamneses and timed up and go test subtasks (sit-to-stand, walking forward, turn, walking back, and turn-to-sit). Data were captured by Qualisys Track Manager software and processed by Visual3D software. The MATLAB program was applied to detect and analyze timed up and go test subtasks. All subtasks differentiated people with Alzheimer's disease and preserved cognition, except the sit-to-stand subtask, which did not distinguish any group. The walking forward subtask differed older people with preserved cognition from mild cognitive impairment, specifically on minimum peak of knee, average value of knee, and hip (pitch axis) during stance phase. The walking back, turn, and turn-to-sit subtasks distinguished subjects with Alzheimer's disease from mild cognitive impairment. The separated analysis of transition and walking subtasks is important in identifying mobility patterns among cognitive profiles.

The role of hip abductor strength on the frontal plane of gait in subjects with medial knee osteoarthritis.

OBJECTIVE: This study aimed to investigate the relationship of hip abductor strength with external hip and knee adduction moments, pain and physical function, and trunk, pelvis, and hip kinematics in the frontal plane during walking in subjects with medial knee osteoarthritis. METHODS: Twenty-five subjects with medial knee osteoarthritis were evaluated through an isokinetic strength test for hip abductor, three-dimensional gait analysis (kinetics and kinematics), and pain and physical function scores. Regression models were used to control the influence of other parameters such as pain, age, gender, severity, walking speed, mass, and height. RESULTS: No relationship was found of hip abductor strength with peak of external knee adduction moment and knee adduction angular impulse. Hip abductor strength explained 17% of contralateral pelvic drop and 21% of hip adduction angle. In addition, hip abductor strength explained 4% and 1% of the variance in the WOMAC physical function score and 40-m fast paced walk test, respectively. CONCLUSION: Considering the relationship of hip abductor strength with contralateral pelvic drop and hip adduction angle, specific exercises might improve physical function and lower limb dynamic alignment during gait.

Performance of Different Timed Up and Go Subtasks in Frailty Syndrome.

BACKGROUND AND PURPOSE: Gait speed, mobility, and postural transitions should be taken into account in older adults with frailty syndrome and can be assessed by the Timed Up and Go (TUG) Test. However, it is unclear which TUG subtasks have greater influence in identifying frail people and whether prefrail individuals present with any reduced subtask performance. The objective of this study was to investigate the differences in performance of TUG subtasks between frail, prefrail, and nonfrail older adults. METHODS: A cross-sectional study was performed with community-dwelling older adults, including 43 nonfrail, 30 prefrail, and 7 frail individuals. The TUG subtasks (sit-to-stand, walking forward, turning, walking back, and turn-to-sit) were assessed using a Qualisys motion system. Data were captured by Qualisys Track Manager software and processed by Visual 3D software. The Matlab program was used to detect, separate, and analyze the TUG subtasks. Statistical significance was set at α= .05 and SigmaPlot software (11.0) was used. RESULTS AND DISCUSSION: The total time to complete the TUG was significantly longer among frail participants than among those who were prefrail and nonfrail. Statistically significant differences in temporal parameters in the turning, walking forward, and walking back subtasks between nonfrail/prefrail and frail older people were found. In addition, the transition TUG subtasks (average and peak velocities of the trunk) distinguished the frail group from the other groups, demonstrating altered quality of movement. CONCLUSIONS: The findings support the value of analyzing the TUG subtasks to improve understanding of mobility deficits in frailty syndrome.

Cryotherapy reduces muscle hypertonia, but does not affect lower limb strength or gait kinematics post-stroke: a randomized controlled crossover study.

BACKGROUND: Based on the premise that spasticity might affect gait post-stroke, cryotherapy is among the techniques used to temporarily reduce spasticity in neurological patients. This effective technique would enhance muscle performance, and ultimately, functional training, such as walking. However, understanding whether a decrease in spasticity level, if any, would lead to improving muscle performance and gait parameters is not based on evidence and needs to be clarified. OBJECTIVES: to investigate the immediate effects of cryotherapy, applied to spastic plantarflexor muscles of subjects post-stroke, on tonus level, torque generation capacity of plantarflexors and dorsiflexors, and angular/spatiotemporal gait parameters. METHODS: Sixteen chronic hemiparetic subjects participated in this randomized controlled crossover study. Cryotherapy (ice pack) or Control (room temperature sand pack) were applied to the calf muscles of the paretic limb. The measurements taken (before and immediately after intervention) were: 1) Tonus according to the Modified Ashworth Scale; 2) Torque assessments were performed using an isokinetic dynamometer; and 3) Spatiotemporal and angular kinematics of the hip, knee, and ankle (flexion/extension), obtained using a tridimensional movement analysis system (Qualisys). RESULTS: Cryotherapy decreased plantarflexor tonus but did not change muscle torque generation capacity and did not affect spatiotemporal or angular parameters during gait compared to control application. These findings contribute to the evidence-based approach to clinical rehabilitation post-stroke. CONCLUSIONS: The findings of this study suggest that cryotherapy applied to the calf muscles of subjects with chronic hemiparesis reduces muscle hypertonia but does not improve dorsiflexors and plantarflexors performance and gait parameters.

Effects of three gait retraining techniques in runners with patellofemoral pain.

OBJECTIVES: Analyze the effects of 3 gait retraining: forefoot landing (FFOOT), 10% step rate increase (SR10%) and forward trunk lean (FTL) on lower limb biomechanics and clinical measurements in patellofemoral pain (PFP) runners. DESIGN: Case series report. SETTINGS: Biomechanical laboratory and treadmill running. PARTICIPANTS: Eighteen recreational PFP runners randomized in 3 groups. MAIN OUTCOME MEASURES: Lower limb kinematics and muscle activation were assessed at baseline and 2-week post-training. Pain intensity and function limitation, measured by AKPS (Anterior Knee Pain Scale) and LEFS (Lower Extremity Functional Scale) assessed at baseline, post-training and 6-month follow-up. Repeated measures analysis of variance was used to compare the effects of gait retraining. RESULTS: FFOOT and FTL increased the AKPS score at post-training(P = .001; P = .008) and 6-month follow-up(P < .001; P < .001). SR10% increased the AKPS score from baseline to 6-month follow-up(P = .006). Pain and LEFS score were improved after gait retraining regardless group. FFOOT presented greater gastrocnemius(P = .037) and rectus femoris pre-activation(P = .006) at post-retraining session. Gait retraining reduced the muscle activity during stance phase and increased during the late-swing regardless group. CONCLUSION: The three techniques presented clinical benefits, improvement of pain symptoms and functional scores, was not accompanied with significant biomechanics differences that could entirely explain this clinical improvement after the intervention.

Relationship of hip and ankle range of motion, trunk muscle endurance with knee valgus and dynamic balance in males.

OBJECTIVES: Investigate the relationship of hip internal rotation (IR) and ankle dorsiflexion (DF) range of motion (ROM), trunk flexor, extensor, and lateral flexor muscle endurance with frontal plane knee projection angle (FPKPA) and Y-balance test (YBT). STUDY DESIGN: Cross-sectional study. SETTING: Armed Force training site. PARTICIPANTS: 121 healthy male militaries with no history of musculoskeletal injury in the last 6 months. MAIN OUTCOMES: FPKPA was evaluated during single-leg squat. YBT was assessed on the anterior, posterolateral and posteromedial directions. Passive hip IR ROM and weight-bearing ankle DF ROM were measured with a digital inclinometer. Trunk muscle endurance was measured as the time the participant could hold the positions. RESULTS: FPKPA was predicted by ankle DF ROM and hip IR ROM (r2 = 0.340; P = 0.009). For YBT anterior, ankle DF ROM was the only predictor (r2 = 0.32; P < 0.001); whereas trunk extensor endurance predicted YBT posterolateral (r2 = 0.273; P < 0.001) and YBT posteromedial (r2 = 0.033; P = 0.045). CONCLUSION: The results suggest that increasing hip stiffness and ankle mobility might help to control dynamic knee alignment. In addition, the dynamic balance could be improved increasing ankle DF ROM and trunk extensor endurance.

Performances on the Timed Up and Go Test and subtasks between fallers and non-fallers in older adults with cognitive impairment.

This work aimed to compare performances on the Timed Up and Go (TUG) test and its subtasks between faller and non-faller older adults with mild cognitive impairment (MCI) and mild Alzheimer's disease (AD). A prospective study was conducted, with 38 older adults with MCI and 37 with mild AD. Participants underwent an assessment at baseline (the TUG and its subtasks using the Qualisys ProReflex system) and the monitoring of falls at the six-month follow up. After six months, 52.6% participants with MCI and 51.3% with AD fell. In accordance with specific subtasks, total performance on the TUG distinguished fallers from non-fallers with AD, fallers from non-fallers with MCI and non-fallers with MCI from non-fallers with AD. Although no other difference was found in total performances, non-fallers with MCI and fallers with AD differed on the walking forward, turn and turn-to-sit subtasks; and fallers with MCI and non-fallers with AD differed on the turn-to-sit subtask.

Core stability, shoulder peak torque and function in throwing athletes with and without shoulder pain.

OBJECTIVE: This study compared core stability, shoulder isokinetic peak torque and shoulder function in throwers with and without shoulder pain. DESIGN: Cross-sectional study. SETTINGS: Throwing athletes. PARTICIPANTS: Thirty healthy athletes and 21 with shoulder pain were included. MAIN OUTCOME MEASURES: Endurance time of the trunk, the modified star excursion balance test, isokinetic peak torque of internal and external rotation of the shoulder, questionnaires, level of satisfaction with the throwing arm and active range of motion. RESULTS: The symptomatic athletes presented with shorter endurance time for the trunk lateral flexors (P < .05), and decreased reach distance for both limbs in the posteromedial direction (P < .05) and for takeoff limb in the posterolateral direction (P = .04), and smaller composite score for both limbs (P < .05) during star excursion balance test as compared to the healthy ones. No significant differences between groups were found for peak torque of internal and external rotation of the shoulder. Athletes with shoulder pain demonstrated more shoulder disability and a lower level of satisfaction with the throwing arm (P = .000). Range of motion was not different between groups for shoulder internal and external rotation. CONCLUSION: Throwing athletes with shoulder pain have lower core stability and shoulder function compared to healthy athletes.

The relationship between external knee moments and muscle co-activation in subjects with medial knee osteoarthritis.

PURPOSE: External knee moments are reliable to measure knee load but it does not take into account muscle activity. Considering that muscle co-activation increases compressive forces at the knee joint, identifying relationships between muscle co-activations and knee joint load would complement the investigation of the knee loading in subjects with knee osteoarthritis. The purpose of this study was to identify relationships between muscle co-activation and external knee moments during walking in subjects with medial knee osteoarthritis. METHODS: 19 controls (11 males, aged 56.6±5, and BMI 25.2±3.3) and 25 subjects with medial knee osteoarthritis (12 males, aged 57.3±5.3, and BMI 28.2±4) were included in this study. Knee adduction and flexion moments, and co-activation (ratios and sums of quadriceps, hamstring, and gastrocnemius) were assessed during walking and compared between groups. The relationship between knee moments and co-activation was investigated in both groups. FINDINGS: Subjects with knee osteoarthritis presented a moderate and strong correlation between co-activation (ratios and sums) and knee moments. INTERPRETATION: Muscle co-activation should be used to measure the contribution of quadriceps, hamstring, and gastrocnemius on knee loading. This information would cooperate to develop a more comprehensive approach of knee loading in this population.

Identification of Directed Interactions in Kinematic Data during Running.

The knowledge of motion dynamics during running activity is crucial to enhance the development of rehabilitation techniques and injury prevention programs. Recent studies investigated the interaction between joints, using several analysis techniques, as cross-correlation, sensitivity analysis, among others. However, the direction of the joints pairing is still not understood. This paper proposes a study of the influence direction pattern in healthy runners by using kinematic data together with partial directed coherence, a frequency approach of Granger causality. The analysis was divided into three anatomical planes, sagittal, frontal, and transverse, and using data from ankle, knee, hip, and trunk segments. Results indicate a predominance of proximal to distal influence during running, reflecting a centralized anatomic source of movements. These findings highlight the necessity of managing proximal joints movements, in addition to motor control and core (trunk and hip) strengthening training to lumbar spine, knee, and ankle injuries prevention and rehabilitation.

Cognitive Correlates of Timed Up and Go Subtasks in Older People With Preserved Cognition, Mild Cognitive Impairment, and Alzheimer's Disease.

OBJECTIVE: To determine whether impaired Timed Up and Go Test (TUG) subtask performances are associated with specific cognitive domains among older people with preserved cognition (PC), mild cognitive impairment (MCI), and mild Alzheimer's disease (AD). DESIGN: TUG subtasks performances were assessed by the Qualisys motion system. Cognition was assessed by Addenbrooke's Cognitive Examination and the Frontal Assessment Battery (FAB). RESULTS: The highest correlations with transition subtasks were with aspects of executive function, i.e. the fluency domain in the PC group (n = 40), FAB scores in the MCI group (n = 40), and the visuospatial domain in the AD group (n = 38). No significant associations were found between the walking subtasks and cognition in any group. Multivariate linear regression models identified the fluency domain as an independent predictor of turn-to-walk and turn-to-sit measures in the PC group, and the visuospatial domain as an independent predictor of turn-to-walk and turn-to-sit measures in the AD group, adjusted for age and sex. CONCLUSIONS: Poorer executive functioning was associated with impaired transition mobility in all groups. The significant associations between visuospatial impairment and poor transition mobility in the AD participants may provide insight into why this group has an elevated fall risk.

Inter- and intra-rater reliability of 3D kinematics during maximum mouth opening of asymptomatic subjects.

Previous studies evaluated 3D human jaw movements using kinematic analysis systems during mouth opening, but information on the reliability of such measurements is still scarce. The purpose of this study was to analyze within- and between-session reliabilities, inter-rater reliability, standard error of measurement (SEM), minimum detectable change (MDC) and consistency of agreement across raters and sessions of 3D kinematic variables during maximum mouth opening (MMO). Thirty-six asymptomatic subjects from both genders were evaluated on two different days, five to seven days apart. Subjects performed three MMO movements while kinematic data were collected. Intraclass correlation coefficient (ICC), SEM and MDC were calculated for all variables, and Bland-Altman plots were constructed. Jaw radius and width were the most reproducible variables (ICC>0.81) and demonstrated minor error. Incisor displacement during MMO and angular movements in the sagittal plane presented good reliability (ICC from 0.61 to 0.8) and small errors and, consequently, could be used in future studies with the same methodology and population. The variables with smaller amplitudes (condylar translations during mouth opening and closing and mandibular movements on the frontal and transversal planes) were less reliable (ICC<0.61) and presented larger SEM and MDC. Although ICC, SEM and MDC showed less between-session reproducibility than within-session and inter-rater, the limits of agreement were larger in inter-rater comparisons. In future studies care must be taken with variables collected on different days and with mandibular movements in the frontal and transversal planes.